Estimating the number of persons who inject drugs in the united states by meta-analysis to calculate national rates of HIV and hepatitis C virus infections

Changes in injecting versus smoking heroin, fentanyl, and methamphetamine among people who inject drugs in San Diego, California, 2020 to 2023

Background

Amidst a rapidly evolving drug supply in North America, people who inject drugs may be transitioning to smoking them. We aimed to assess changes in injecting and smoking heroin, fentanyl and methamphetamine among a cohort of people who injected drugs at baseline from San Diego, California.

Methods

Over five six-month periods spanning October 2020-April 2023, we assessed prevalence of injecting and smoking opioids or methamphetamine and whether participants used these drugs more frequently by smoking than injecting. Multivariable Poisson regression via Generalized Estimating Equations was used to examine time trends.

Results

Of 362 participants, median age was 40 years; most were male (72%), non-Hispanic (55%), and unhoused (67%). Among this cohort, of whom 100% injected (or injected and smoked) at baseline, by period five (two years later), 34% reported only smoking, while 59% injected and smoked, and 7% only injected. By period five, the adjusted relative risk (aRR) of injecting opioids was 0.41 (95% Confidence Interval [CI]: 0.33, 0.51) compared to period one, and the aRR for injecting methamphetamine was 0.50 (95% CI: 0.39, 0.63). Compared to period one, risks for smoking fentanyl rose significantly during period three (aRR=1.44, 95% CI: 1.06, 1.94), four (aRR=1.65, 95% CI: 1.24, 2.20) and five (aRR=1.90, 95% CI: 1.43, 2.53). Risks for smoking heroin and methamphetamine more frequently than injecting these drugs increased across all periods.

Conclusions

Opioid and methamphetamine injection declined precipitously, with notable increases in smoking these drugs. Research is urgently needed to understand the health consequences of these trends.

Social-spatial network structures among young urban and suburban persons who inject drugs in a large metropolitan area

BACKGROUND

Recent studies underscore the significance of adopting a syndemics approach to study opioid misuse, overdose, hepatitis C (HCV) and HIV infections, within the broader context of social and environmental contexts in already marginalized communities. Social interactions and spatial contexts are crucial structural factors that remain relatively underexplored. This study examines the intersections of social interactions and spatial contexts around injection drug use. More specifically, we investigate the experiences of different residential groups among young (aged 18-30) people who inject drugs (PWID) regarding their social interactions, travel behaviors, and locations connected to their risk behaviors. By doing so, we aim to achieve a more comprehensive understanding of the multidimensional risk environment, thereby facilitating the development of informed policies.

METHODS

We collected and examined data regarding young PWID's egocentric injection network and geographic activity spaces (i.e., where they reside, inject drugs, purchase drugs, and meet sex partners). Participants were stratified based on the location of all place(s) of residence in the past year i.e., urban, suburban, and transient (both urban and suburban) to i) elucidate geospatial concentration of risk activities within multidimensional risk environments based on kernel density estimates; and ii) examine spatialized social networks for each residential group.

RESULTS

Participants were mostly non-Hispanic white (59%); 42% were urban residents, 28% suburban, and 30% transient. We identified a spatial area with concentrated risky activities for each residential group on the West side of Chicago in Illinois where a large outdoor drug market area is located. The urban group (80%) reported a smaller concentrated area (14 census tracts) compared to the transient (93%) and suburban (91%) with 30 and 51 tracts, respectively. Compared to other areas in Chicago, the identified area had significantly higher neighborhood disadvantages. Significant differences were observed in social network structures and travel behaviors: suburban participants had the most homogenous network in terms of age and residence, transient participants had the largest network (degree) and more non-redundant connections, while the urban group had the shortest travel distance for all types of risk activities.

CONCLUSION

Distinct residential groups exhibit varying patterns of network interaction, travel behaviors, and geographical contexts related to their risk behaviors. Nonetheless, these groups share common concentrated risk activity spaces in a large outdoor urban drug market area, underscoring the significance of accounting for risk spaces and social networks in addressing syndemics within PWID populations.

Trends in Hepatitis C Virus and HIV Care Outcomes Among People With HIV in Georgia, United States, 2014-2019

OBJECTIVE

If untreated, hepatitis C virus (HCV) leads to poor health outcomes, including liver disease and death, particularly among people with HIV (PWH). We describe trends over time in incidence rates of HCV diagnoses among PWH in the state of Georgia.

METHODS

We constructed a retrospective cohort of PWH in Georgia by using matched HIV and HCV case surveillance data from people diagnosed with HCV infection from January 1, 2014, through December 31, 2019. We calculated annual incidence rates per 1000 person-years and estimated trends over time in HCV diagnoses among the cohort of PWH by demographic characteristics and HIV care outcomes using Poisson regression analysis, with α = .05 considered significant.

RESULTS

From 2014 through 2019, among 49 530 PWH in Georgia, 1945 (3.9%) were diagnosed with HCV infection. During this period, overall incidence per 1000 person-years of newly diagnosed HCV infection among PWH decreased from 8.7 to 4.5 (P for trend < .001). However, from 2014 through 2019, the annual incidence rates of PWH who were newly diagnosed with HCV infection increased from 4.6 to 7.1 (P for trend = .003) among people born from 1980 through 1989 and from 3.3 to 12.8 (P for trend < .001) among people born in 1990 or later.

CONCLUSION

Strategies are needed to increase prevention, diagnosis, and treatment of HIV/HCV coinfection, particularly among PWH born in 1980 and later. Routine linkage of state surveillance data can inform prioritization of PWH at highest risk of HCV infection.

A Note on Preexposure Prophylaxis Preferences Among Women Who Inject Drugs

ABSTRACT

We informed women who inject drugs about different preexposure prophylaxis (PrEP) formulations; they then ranked their preferences. Daily oral PrEP was most preferred, followed by injectable PrEP and vaginal rings/gels, especially among women of color. Multiple PrEP options should be discussed with women who inject drugs to increase uptake.

Integrating harm reduction into acute care: A single center's experience

Objective

Injection drug use (IDU) is prevalent in North America and is associated with presentations with infective endocarditis. Supporting patients who present with infective endocarditis related to IDU through harm reduction, a pragmatic approach to reduce secondary harms of a health behavior, helps address the underlying IDU. We share a case exemplar of how one acute care facility integrated harm-reduction practices into daily patient care.

Methods

We took a 3-stage approach to integrate harm-reduction practices into daily patient care. In stage 1, we raised awareness and knowledge of harm reduction through education. In stage 2, we provided explicit support for harm reduction. In stage 3, we provided tangible tools to support harm reduction.

Results

More than 300 staff attended education sessions and reported increased knowledge related to substances, harm reduction, and engaging patients who use substances in conversations. Staff requested the hospital explicitly support harm reduction, which led to stage 2. The creation of a harm-reduction philosophy statement provided permission to engage in harm-reduction practices. Stage 3 included the creation of a harm-reduction supply distribution program and consultations with Addictions Medicine and treatment programs. The implementation of harm-reduction supply distribution was successful and is being spread across the facility.

Conclusions

Engaging in harm-reduction practices within an acute care facility is possible through a multistage process focused on education, explicit support, and tangible tools. Spreading harm-reduction integration and working with patients who used substances to evaluate effectiveness are key next steps.

Estimating Causal Effects of HIV Prevention Interventions with Interference in Network-based Studies among People Who Inject Drugs

Evaluating causal effects in the presence of interference is challenging in network-based studies of hard-to-reach populations. Like many such populations, people who inject drugs (PWID) are embedded in social networks and often exert influence on others in their network. In our setting, the study design is observational with a non-randomized network-based HIV prevention intervention. Information is available on each participant and their connections that confer possible HIV risk through injection and sexual behaviors. We considered two inverse probability weighted (IPW) estimators to quantify the population-level spillover effects of non-randomized interventions on subsequent health outcomes. We demonstrated that these two IPW estimators are consistent, asymptotically normal, and derived a closed-form estimator for the asymptotic variance, while allowing for overlapping interference sets (groups of individuals in which the interference is assumed possible). A simulation study was conducted to evaluate the finite-sample performance of the estimators. We analyzed data from the Transmission Reduction Intervention Project, which ascertained a network of PWID and their contacts in Athens, Greece, from 2013 to 2015. We evaluated the effects of community alerts on subsequent HIV risk behavior in this observed network, where the connections or links between participants were defined by using substances or having unprotected sex together. In the study, community alerts were distributed to inform people of recent HIV infections among individuals in close proximity in the observed network. The estimates of the risk differences for spillover using either IPW estimator demonstrated a protective effect. The results suggest that HIV risk behavior could be mitigated by exposure to a community alert when an increased risk of HIV is detected in the network.

A multimorbidity model for estimating health outcomes from the syndemic of injection drug use and associated infections in the United States

BACKGROUND

Fatal drug overdoses and serious injection-related infections are rising in the US. Multiple concurrent infections in people who inject drugs (PWID) exacerbate poor health outcomes, but little is known about how the synergy among infections compounds clinical outcomes and costs. Injection drug use (IDU) converges multiple epidemics into a syndemic in the US, including opioid use and HIV. Estimated rates of new injection-related infections in the US are limited due to widely varying estimates of the number of PWID in the US, and in the absence of clinical trials and nationally representative longitudinal observational studies of PWID, simulation models provide important insights to policymakers for informed decisions.

METHODS

We developed and validated a MultimorbiditY model to Reduce Infections Associated with Drug use (MYRIAD). This microsimulation model of drug use and associated infections (HIV, hepatitis C virus [HCV], and severe bacterial infections) uses inputs derived from published data to estimate national level trends in the US. We used Latin hypercube sampling to calibrate model output against published data from 2015 to 2019 for fatal opioid overdose rates. We internally validated the model for HIV and HCV incidence and bacterial infection hospitalization rates among PWID. We identified best fitting parameter sets that met pre-established goodness-of-fit targets using the Pearson's chi-square test. We externally validated the model by comparing model output to published fatal opioid overdose rates from 2020.

RESULTS

Out of 100 sample parameter sets for opioid use, the model produced 3 sets with well-fitting results to key calibration targets for fatal opioid overdose rates with Pearson's chi-square test ranging from 1.56E-5 to 2.65E-5, and 2 sets that met validation targets. The model produced well-fitting results within validation targets for HIV and HCV incidence and serious bacterial infection hospitalization rates. From 2015 to 2019, the model estimated 120,000 injection-related overdose deaths, 17,000 new HIV infections, and 144,000 new HCV infections among PWID.

CONCLUSIONS

This multimorbidity microsimulation model, populated with data from national surveillance data and published literature, accurately replicated fatal opioid overdose, incidence of HIV and HCV, and serious bacterial infections hospitalization rates. The MYRIAD model of IDU could be an important tool to assess clinical and economic outcomes related to IDU behavior and infections with serious morbidity and mortality for PWID.

The relationship of PrEP beliefs to perceived personal, interpersonal and structural benefits and barriers to PrEP use in women who inject drugs

BACKGROUND

Women who inject drugs (WWID) have significant biological, behavioral, and gender-based barriers to accessing HIV prevention services, including Pre-Exposure Prophylaxis (PrEP) medication. Little is known about how beliefs about PrEP impact both perceived barriers and benefits of PrEP use and how they may be related to the decision-making process.

METHODS

Surveys were conducted with 100 female clients of a large syringe services program in Philadelphia, Pennsylvania. The sample was categorized into three groups based on mean PrEP beliefs scores using terciles: accurate beliefs, moderately accurate beliefs, and inaccurate beliefs. Oneway ANOVA tests were used to compare groups by perceived benefits and barriers to PrEP, drug use stigma, healthcare beliefs, patient self-advocacy, and intention to use PrEP.

RESULTS

Participants had a mean age of 39 years (SD 9.00), 66% reported being White, 74% finished high school, and 80% reported having been homeless within the past 6 months. Those with the most accurate PrEP beliefs reported highest intent to use PrEP and were more likely to agree that benefits of PrEP included it preventing HIV and helping them "feel in charge". Those with inaccurate beliefs were more likely to strongly agree that barriers, such as fear of reprisal from a partner, potential theft, or feeling they "might get HIV anyway", were reasons not to use PrEP.

CONCLUSIONS

Results indicate perceived personal, interpersonal and structural barriers to PrEP use are associated with accuracy of beliefs is, pointing to important intervention targets to increase uptake among WWID.

Estimated Clinical Outcomes and Cost-effectiveness Associated With Provision of Addiction Treatment in US Primary Care Clinics

Importance

US primary care practitioners (PCPs) are the largest clinical workforce, but few provide addiction care. Primary care is a practical place to expand addiction services, including buprenorphine and harm reduction kits, yet the clinical outcomes and health care sector costs are unknown.

Objective

To estimate the long-term clinical outcomes, costs, and cost-effectiveness of integrated buprenorphine and harm reduction kits in primary care for people who inject opioids.

Design, Setting, and Participants

In this modeling study, the Reducing Infections Related to Drug Use Cost-Effectiveness (REDUCE) microsimulation model, which tracks serious injection-related infections, overdose, hospitalization, and death, was used to examine the following treatment strategies: (1) PCP services with external referral to addiction care (status quo), (2) PCP services plus onsite buprenorphine prescribing with referral to offsite harm reduction kits (BUP), and (3) PCP services plus onsite buprenorphine prescribing and harm reduction kits (BUP plus HR). Model inputs were derived from clinical trials and observational cohorts, and costs were discounted annually at 3%. The cost-effectiveness was evaluated over a lifetime from the modified health care sector perspective, and sensitivity analyses were performed to address uncertainty. Model simulation began January 1, 2021, and ran for the entire lifetime of the cohort.

Main Outcomes and Measures

Life-years (LYs), hospitalizations, mortality from sequelae (overdose, severe skin and soft tissue infections, and endocarditis), costs, and incremental cost-effectiveness ratios (ICERs).

Results

The simulated cohort included 2.25 million people and reflected the age and gender of US persons who inject opioids. Status quo resulted in 6.56 discounted LYs at a discounted cost of $203 500 per person (95% credible interval, $203 000-$222 000). Each strategy extended discounted life expectancy: BUP by 0.16 years and BUP plus HR by 0.17 years. Compared with status quo, BUP plus HR reduced sequelae-related mortality by 33%. The mean discounted lifetime cost per person of BUP and BUP plus HR were more than that of the status quo strategy. The dominating strategy was BUP plus HR. Compared with status quo, BUP plus HR was cost-effective (ICER, $34 400 per LY). During a 5-year time horizon, BUP plus HR cost an individual PCP practice approximately $13 000.

Conclusions and Relevance

This modeling study of integrated addiction service in primary care found improved clinical outcomes and modestly increased costs. The integration of addiction service into primary care practices should be a health care system priority.

Social-spatial network structures among young urban and suburban persons who inject drugs in a large metropolitan area

Background

It is estimated that there are 1.5% US adult population who inject drugs in 2018, with young adults aged 18-39 showing the highest prevalence. PWID are at a high risk of many blood-borne infections. Recent studies have highlight the importance of employing the syndemic approach to study opioid misuse, overdose, HCV and HIV, along with the social and environmental contexts where these interrelated epidemics occur in already marginalized communities. Social interactions and spatial contexts are important structural factors that are understudied.

Methods

Egocentric injection network and geographic activity spaces for young (aged 18-30) PWID and their injection, sexual, and social support network members (i.e., where reside, inject drugs, purchase drugs, and meet sex partners) were examined using baseline data from an ongoing longitudinal study (n=258). Participants were stratified based on the location of all place(s) of residence in the past year i.e., urban, suburban, and transient (both urban and suburban) to i) elucidate geospatial concentration of risk activities within multi-dimensional risk environments based on kernel density estimates; and ii) examine spatialized social networks for each residential group.

Results

Participants were mostly non-Hispanic white (59%); 42% were urban residents, 28% suburban, and 30% transient. We identified a spatial area with concentrated risky activities for each residence group on the West side of Chicago where a large outdoor drug market area is located. The urban group (80%) reported a smaller concentrated area (14 census tracts) compared to the transient (93%) and suburban (91%) with 30 and 51 tracts, respectively. Compared to other areas in Chicago, the identified area had significantly higher neighborhood disadvantages (e.g., higher poverty rate, p <0.001). Significant ( p <0.01 for all) differences were observed in social network structures: suburban had the most homogenous network in terms of age and residence, transient participants had the largest network (degree) and more non-redundant connections.

Conclusion

We identified concentrated risk activity spaces among PWID from urban, suburban, and transient groups in a large outdoor urban drug market area, which highlights the need for considering the role of risk spaces and social networks in addressing the syndemics in PWID populations.

Factors associated with receptive injection equipment sharing among people who inject drugs: findings from a multistate study at the start of the COVID-19 pandemic

BACKGROUND

Receptive injection equipment sharing (i.e., injecting with syringes, cookers, rinse water previously used by another person) plays a central role in the transmission of infectious diseases (e.g., HIV, viral hepatitis) among people who inject drugs. Better understanding these behaviors in the context of COVID-19 may afford insights about potential intervention opportunities in future health crises.

OBJECTIVE

This study examines factors associated with receptive injection equipment sharing among people who inject drugs in the context of COVID-19.

METHODS

From August 2020 to January 2021, people who inject drugs were recruited from 22 substance use disorder treatment programs and harm reduction service providers in nine states and the District of Columbia to complete a survey that ascertained how the COVID-19 pandemic affected substance use behaviors. We used logistic regression to identify factors associated with people who inject drugs having recently engaged in receptive injection equipment sharing.

RESULTS

One in four people who inject drugs in our sample reported having engaged in receptive injection equipment sharing in the past month. Factors associated with greater odds of receptive injection equipment sharing included: having a high school education or equivalent (adjusted odds ratio [aOR] = 2.14, 95% confidence interval [95% CI] 1.24, 3.69), experiencing hunger at least weekly (aOR = 1.89, 95% CI 1.01, 3.56), and number of drugs injected (aOR = 1.15, 95% CI 1.02, 1.30). Older age (aOR = 0.97, 95% CI 0.94, 1.00) and living in a non-metropolitan area (aOR = 0.43, 95% CI 0.18, 1.02) were marginally associated with decreased odds of receptive injection equipment sharing.

CONCLUSIONS

Receptive injection equipment sharing was relatively common among our sample during the early months of the COVID-19 pandemic. Our findings contribute to existing literature that examines receptive injection equipment sharing by demonstrating that this behavior was associated with factors identified in similar research that occurred before COVID. Eliminating high-risk injection practices among people who inject drugs requires investments in low-threshold and evidence-based services that ensure persons have access to sterile injection equipment.

Project T-SHARP: study protocol for a multi-site randomized controlled trial of tele-harm reduction for people with HIV who inject drugs

BACKGROUND

The resurgence of HIV outbreaks and rising prevalence among people who inject drugs (PWID) remain exigent obstacles to Ending the HIV Epidemic in the USA. Adapting a low threshold, comprehensive treatment model for PWID with HIV can leverage syringe services programs (SSPs) to increase availability and accessibility of antiretrovirals (ART), medications for opioid use disorder (MOUD), and hepatitis C cure. We developed Tele-Harm Reduction, a telehealth-enhanced, harm reduction intervention delivered within an SSP venue.

METHODS

The T-SHARP trial is an open-label, multi-site, randomized controlled superiority trial with two parallel treatment arms. Participants (n=240) recruited from SSPs in Miami, Ft. Lauderdale, and Tampa, Florida, who are PWID with uncontrolled HIV (i.e., HIV RNA>200) will be randomized to Tele-Harm Reduction or off-site linkage to HIV care. The primary objective is to compare the efficacy of Tele-Harm Reduction for initiation of ART at SSPs vs. off-site linkage to an HIV clinic with respect to viral suppression across follow-up (suppression at 3, 6, and 12 months post randomization). Participants with HIV RNA<200 copies/ml will be considered virally suppressed. The primary trial outcome is time-averaged HIV viral suppression (HIV RNA <200 copies/ml) over 3-, 6-, and 12-month follow-up. Secondary outcomes include initiation of MOUD measured by urine drug screen and HCV cure, defined as achieving 12-week sustained virologic response (negative HCV RNA at 12 weeks post treatment completion). A cost-effectiveness analysis will be performed.

DISCUSSION

The T-SHARP Trial will be the first to our knowledge to test the efficacy of an innovative telehealth intervention with PWID with uncontrolled HIV delivered via an SSP to support HIV viral suppression. Tele-Harm Reduction is further facilitated by a peer to support adherence and bridge the digital divide. This innovative, flipped healthcare model sets aside the traditional healthcare system, reduces multi-level barriers to care, and meets PWID where they are. The T-SHARP trial is a pragmatic clinical trial that seeks to transform the way that PWID access HIV care and improve HIV clinical outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05208697. Trial registry name: Tele-Harm Reduction. Registration date: January 26, 2022.

Estimated Number of People Who Inject Drugs in the United States

BACKGROUND

Public health data signal increases in the number of people who inject drugs (PWID) in the United States during the past decade. An updated PWID population size estimate is critical for informing interventions and policies aiming to reduce injection-associated infections and overdose, as well as to provide a baseline for assessments of pandemic-related changes in injection drug use.

METHODS

We used a modified multiplier approach to estimate the number of adults who injected drugs in the United States in 2018. We deduced the estimated number of nonfatal overdose events among PWID from 2 of our previously published estimates: the number of injection-involved overdose deaths and the meta-analyzed ratio of nonfatal to fatal overdose. The number of nonfatal overdose events was divided by prevalence of nonfatal overdose among current PWID for a population size estimate.

RESULTS

There were an estimated 3 694 500 (95% confidence interval [CI], 1 872 700-7 273 300) PWID in the United States in 2018, representing 1.46% (95% CI, .74-2.87) of the adult population. The estimated prevalence of injection drug use was highest among males (2.1%; 95% CI, 1.1-4.2), non-Hispanic Whites (1.8%; 95% CI, .9-3.6), and adults aged 18-39 years (1.8%; 95% CI, .9-3.6).

CONCLUSIONS

Using transparent, replicable methods and largely publicly available data, we provide the first update to the number of people who inject drugs in the United States in nearly 10 years. Findings suggest the population size of PWID has substantially grown in the past decade and that prevention services for PWID should be proportionally increased.

La santé sexuelle des hommes trans : entre problèmes de catégorisation et invisibilisation

INTRODUCTION

Sexual minorities have been disproportionally impacted by the HIV-Aids epidemic. Their high prevalence motivated sexual health research that first focused on gay men, then trans women. Trans men have been considered at very low risk of exposition, Hence the scarce number of research about them. However, an emerging literature is showing diversified and surprising results regarding the reasons for their initial exclusion.

PURPOSE OF RESEARCH

This article seeks to establish the state of knowledge on trans men's sexual health through a French and international literature review.

RESULTS

Trans men have a variety of partners, sexual and non-sexual practices (IDU) that leads to categorize them at high risk of HIV exposure. The proportion of trans men who are HIV positive still is difficult to assess. It is estimated to be high in the USA, and close to zero in France. Low screening rates, difficulties accessing health care, and identification problems in the very classification of people suggest that they might be more of them. Trans men also report discriminations in access to health care services, and specific health vulnerabilities. Gynecology and reproductive health are rarely even mentioned.

CONCLUSIONS

Rethinking the categories used in research would produce a more accurate representation of the varied realities of trans people.

Modeling HCV elimination recovery following the COVID-19 pandemic in the United States: Pathways to regain progress

BACKGROUND

As of 2019, the United States (US) was not on track to achieve targets for elimination, due to increasing incidence and treatment barriers. In 2020, the COVID-19 pandemic disrupted HCV services globally and in the US. As healthcare services normalize, there is an urgent need to reassess progress and evaluate scenarios that restore a pathway toward HCV elimination.

METHODS

We updated a validated Markov model to estimate HCV-related morbidity and mortality in the US. Five scenarios were developed to bookend possible HCV outcomes in the wake of the pandemic. These included 1) return to pre-COVID-19 treatment forecasts; 2) achieve elimination targets through treatment and harm reduction; 3) long-term treatment disruptions; 4/5) achieve elimination targets through increased treatment without increased harm reduction, starting in either 2022 or 2025.

FINDINGS

From 2014-2019, more than 1.2 million patients were treated for HCV in the US. Elimination targets in 2030 could be achieved in the US by treating an additional 3.2-3.3 million patients from 2020 to 2030, or by preventing new infections through expanded harm reduction programs and treating up to 2.7 million patients. Intervention scenarios could prevent over 30,000 HCC cases and over 29,000 liver-related deaths.

INTERPRETATION

The US has made strides toward HCV elimination, but gains could be lost in the wake of the pandemic. However, it is still possible to avert nearly 30,000 deaths through increased harm reduction and increased treatment rates. This requires a coordinated effort from the entire HCV community.

Prevalence and factors associated with neck injection among people who inject drugs in San Francisco, California

BACKGROUND

Groin and neck injections are generally a last resort for people who inject drugs (PWID) who do not have easy access to functioning veins. These alternative injection practices can lead to an increased likelihood of adverse health outcomes. There is still much we do not know about groin and neck injections among PWID in the US, as the literature to-date comes from studies primarily focused on groin injections outside the US. We assessed prevalence, predictors, and associated behaviors of neck injection through a survey fielded in San Francisco, California, US.

METHODS

The sample comes from a longitudinal observational study that used targeted sampling to recruit PWID in San Francisco. The current study sample includes 239 PWID who completed their 12-month survey between June 2019 and June 2020.

RESULTS

About a third of the sample reported injecting in their neck in the past 30 days, with the most common reason being lack of available veins. Age, past 6-month abscess / soft tissue infection, and past 30-day use of opioids mixed with cocaine were significantly associated with past 30-day neck injection in the final multivariate model. Past 30-day neck injection was also significantly associated with being injected by another person in the past 30 days.

CONCLUSIONS

PWID at higher risk for vein deterioration were more likely to inject into their neck. Harm reduction strategies such as safer injection counseling, safe smoking supplies, use of "street doctors," and safe consumption sites may reduce instances of neck injection and/or associated health risks.

Trends and distinct profiles of persons who inject drugs in the United States, 2015-2019

Drug injection represents a major health problem in the US, with severe health consequences including the transmission of blood-borne infections. An examination of the most recent trends in drug injection is warranted by the fast-evolving drug epidemic and recent policy changes such as the federal funding ban on needle exchange programs. This research examines current drug injection trends, patterns, and socioeconomic and behavioral profiles of people who inject drugs (PWID). Data were derived from the 2002 to 2019 National Survey on Drug Use and Health (NSDUH). After examining the annual prevalence of drug injection since 2002, a latent class analysis was conducted to identify drug injection and other substance misuse patterns among PWID using the latest (2015-2019) NSDUH datasets. Associations between class membership and behavioral health comorbidities and treatment receipt were also assessed. The drug injection prevalence among US adults aged 18-64 increased from 0.21% in 2002/2004 to 0.36% in 2017/2019. Three distinctive groups were identified: the heroin injection group (45.2%), the methamphetamine injection group (28.0%), and the multi-drug injection group (26.8%). The methamphetamine injection group reported greater risks of experiencing serious psychological distress, suicidality, and limited substance use treatment. Special attention is needed for those who primarily injected methamphetamine. Programs to promote harm reduction and increase access to addiction treatment need to be expanded in at-risk communities while accounting for their distinct socioeconomic and drug use/misuse profiles.

Impact of age and gender disparity on CD4+ cell counts to control disease progression using specific HAART in HIV-1 positive patients: A case-control study

BACKGROUND

Highly Active Antiretroviral Therapy (HAART) is composed of several drugs in the antiretroviral class to better treat human immunodeficiency virus type 1 (HIV-1) patients. The estimation of CD4+ T cell counts and HIV-1 viral load in plasma is required to evaluate the treatment success of a specific HAART.

METHODOLOGY

The study included the effects of NRTIs (nucleoside reverse transcriptase inhibitors) and novel protease inhibitors (HAART) on normal control subjects and HIV-1 positive subjects from SGPGIMS, Lucknow, with different age groups and genders. Furthermore, the study was conducted by the estimation of HIV through ELISA, measurement of absolute CD4+ cell count, and the measurement of viral load through qRT-PCR. Furthermore, NRTIs (Retrovir and Epivir) were administered orally one tablet daily in the morning followed by newly FDA-approved protease inhibitors (fosamprenavir and darunavir) orally in the evening at the same dose. Furthermore, CD4+T cell counts and HIV-1 viral load were investigated and correlated in patients with different genders and age groups.

RESULT

Administration of NRTIs and novel protease inhibitors (HAART) in HIV patients had a significant effect on the CD4+ cell count in various age intervals among males and females. The mean comparison of viral load distribution based on gender in CD4 +ve patients in the case group exhibited a viral load higher in females compared to males, indicating a statistically significant difference between males and females (p<0.05). A notable association between virological and immunological parameters was observed with a reciprocal relationship between viral load and CD4 cell count in CD4 +ve patients, demonstrating multiple correlation coefficients with an R-value of 0.853.

CONCLUSION

The administration of specific HAART (NRTIs and novel protease inhibitors) in HIV patients had a notable improvement in the CD4+ cell count and viral load with significant age and gender disparity.

Characterization of Risk Factors Among Individuals with a History of Incarceration Presenting to a Sexually Transmitted Infections Clinic: Implications for HIV and STI Prevention and Care

More than 2 million people are incarcerated in the United States with many millions more processed through correctional facilities annually. Communities impacted by incarceration are also disproportionately impacted by the HIV and sexually transmitted infection (STI) epidemics. However, relatively little is known about the behaviors that place individuals with a history of incarceration at risk for HIV/STI acquisition. We utilized clinical data from patients presenting to an STI clinic located in Providence, Rhode Island. A latent class analysis was conducted on reported HIV acquisition risk behavior and STI testing results on a total of 1129 encounters where a history of incarceration was reported. A total of three classes were identified. Class 1 (N = 187, 11%), more frequently reported 10+ sexual partners (45%), an STI diagnosis (48%) and sex while intoxicated (86%) in the past year as well as identifying as a man who has sex with other men (60%). Class 2 (N = 57, 5%) was more likely to report giving (53%) and receiving (44%) money/drugs for sex in the past year as well as a history of injecting drugs (61%) and using methamphetamine (60%). Class 3 (N = 885, 78%) most frequently reported 0-2 sexual partners (48%), identified as Black (27%), Hispanic/Latino (69%) and a man who only has sex with women (80%). Class 1 had significantly higher odds ratio (1.8, 95% confidence interval = 1.3-2.5) of testing HIV/STI positive. The results provide important insights into risk subgroups for those with a history of incarceration at risk of HIV/STI acquisition.

Cancer Screening among Rural People Who Use Drugs: Colliding Risks and Barriers

Rural cancer disparities are associated with lesser healthcare access and screening adherence. The opioid epidemic may increase disparities as people who use drugs (PWUD) frequently experience healthcare-associated stigmatizing experiences which discourage seeking routine care. Rural PWUD were recruited to complete surveys and interviews exploring cancer (cervical, breast, colorectal, lung) risk, screening history, and healthcare experiences. From July 2020–July 2021 we collected 37 surveys and 8 interviews. Participants were 24.3% male, 86.5% White race, and had a mean age of 44.8 years. Females were less likely to report seeing a primary care provider on a regular basis, and more likely to report stigmatizing healthcare experiences. A majority of females reporting receiving recommendations and screens for cervical and breast cancer, but only a minority were adherent. Similarly, only a minority of males and females reported receiving screening tests for colorectal and lung cancer. Screening rates for all cancers were substantially below those for the US generally and rural areas specifically. Interviews confirmed stigmatizing healthcare experiences and suggested screening barriers and possible solutions. The opioid epidemic involves millions of individuals and is disproportionately experienced in rural communities. To avoid exacerbating existing rural cancer disparities, methods to engage PWUD in cancer screening need to be developed.

Simulated Cost-effectiveness and Long-term Clinical Outcomes of Addiction Care and Antibiotic Therapy Strategies for Patients With Injection Drug Use-Associated Infective Endocarditis

IMPORTANCE

Emerging evidence supports the use of outpatient parenteral antimicrobial therapy (OPAT) and, in many cases, partial oral antibiotic therapy for the treatment of injection drug use-associated infective endocarditis (IDU-IE); however, long-term outcomes and cost-effectiveness remain unknown.

OBJECTIVE

To compare the added value of inpatient addiction care services and the cost-effectiveness and clinical outcomes of alternative antibiotic treatment strategies for patients with IDU-IE.

DESIGN, SETTING, AND PARTICIPANTS

This decision analytical modeling study used a validated microsimulation model to compare antibiotic treatment strategies for patients with IDU-IE. Model inputs were derived from clinical trials and observational cohort studies. The model included all patients with injection opioid drug use (N = 5 million) in the US who were eligible to receive OPAT either in the home or at a postacute care facility. Costs were annually discounted at 3%. Cost-effectiveness was evaluated from a health care sector perspective over a lifetime starting in 2020. Probabilistic sensitivity, scenario, and threshold analyses were performed to address uncertainty.

INTERVENTIONS

The model simulated 4 treatment strategies: (1) 4 to 6 weeks of inpatient intravenous (IV) antibiotic therapy along with opioid detoxification (usual care strategy), (2) 4 to 6 weeks of inpatient IV antibiotic therapy along with inpatient addiction care services that offered medication for opioid use disorder (usual care/addiction care strategy), (3) 3 weeks of inpatient IV antibiotic therapy along with addiction care services followed by OPAT (OPAT strategy), and (4) 3 weeks of inpatient IV antibiotic therapy along with addiction care services followed by partial oral antibiotic therapy (partial oral antibiotic strategy).

MAIN OUTCOMES AND MEASURES

Mean percentage of patients completing treatment for IDU-IE, deaths associated with IDU-IE, life expectancy (measured in life-years [LYs]), mean cost per person, and incremental cost-effectiveness ratios (ICERs).

RESULTS

All modeled scenarios were initialized with 5 million individuals (mean age, 42 years; range, 18-64 years; 70% male) who had a history of injection opioid drug use. The usual care strategy resulted in 18.63 LYs at a cost of $416 570 per person, with 77.6% of hospitalized patients completing treatment. Life expectancy was extended by each alternative strategy. The partial oral antibiotic strategy yielded the highest treatment completion rate (80.3%) compared with the OPAT strategy (78.8%) and the usual care/addiction care strategy (77.6%). The OPAT strategy was the least expensive at $412 150 per person. Compared with the OPAT strategy, the partial oral antibiotic strategy had an ICER of $163 370 per LY. Increasing IDU-IE treatment uptake and decreasing treatment discontinuation made the partial oral antibiotic strategy more cost-effective compared with the OPAT strategy. When assuming that all patients with IDU-IE were eligible to receive partial oral antibiotic therapy, the strategy was cost-saving and resulted in 0.0247 additional discounted LYs. When treatment discontinuation was decreased from 3.30% to 2.65% per week, the partial oral antibiotic strategy was cost-effective compared with OPAT at the $100 000 per LY threshold.

CONCLUSIONS AND RELEVANCE

In this decision analytical modeling study, incorporation of OPAT or partial oral antibiotic approaches along with addiction care services for the treatment of patients with IDU-IE was associated with increases in the number of people completing treatment, decreases in mortality, and savings in cost compared with the usual care strategy of providing inpatient IV antibiotic therapy alone.

Modeling alcohol use disorder as a set of interconnected symptoms - Assessing differences between clinical and population samples and across external factors

Alcohol use disorder is argued to be a highly complex disorder influenced by a multitude of factors on different levels. Common research approaches fail to capture this breadth of interconnecting symptoms. To address this gap in theoretical assumptions and methodological approaches, we used a network analysis to assess the interplay of alcohol use disorder symptoms. We applied the exploratory analysis to two US-datasets, a population sample with 23,591 individuals and a clinical sample with 483 individuals seeking treatment for alcohol use disorder. Using a Bayesian framework, we first investigated differences between the clinical and population sample looking at the symptom interactions and underlying structure space. In the population sample the time spent drinking alcohol was most strongly connected, whereas in the clinical sample loss of control showed most connections. Furthermore, the clinical sample demonstrated less connections, however, estimates were too unstable to conclude the sparsity of the network. Second, for the population sample we assessed whether the network was measurement invariant across external factors like age, gender, ethnicity and income. The network differed across all factors, especially for age subgroups, indicating that subgroup specific networks should be considered when deriving implications for theory building or intervention planning. Our findings corroborate known theories of alcohol use disorder stating loss of control as a central symptom in alcohol dependent individuals.

HIV Risk Among Urban and Suburban People Who Inject Drugs: Elevated Risk Among Fentanyl and Cocaine Injectors in Maryland

Drug overdose remains a leading cause of death in the US, with growing rates attributable to illicit fentanyl use. Recent HIV outbreaks among people who inject drugs (PWID) and service disruptions from COVID-19 have renewed concerns on HIV resurgence. We examined the relationship between fentanyl use and three injection-related HIV risk behaviors among PWID in Baltimore City (BC) and Anne Arundel Country (AAC), Maryland. PWID (N = 283) were recruited to the study through targeted sampling at street-based locations in BC and AAC from July 2018 to March 2020. Receptive syringe sharing (RSS) [adjusted odds ratio (AOR): 2.8, 95% confidence interval (CI): 1.2–6.3] and daily injecting (AOR: 1.9, 95% CI: 1.0–3.6) were associated with injecting fentanyl and cocaine together. Fentanyl availability and COVID-19 bring new HIV prevention challenges, particularly among those who inject fentanyl with cocaine, highlighting the importance to expand and sustain harm reduction, prevention, and treatment services for PWID to reduce HIV and overdose burden.

Participants of a mail delivery syringe services program are underserved by other safe sources for sterile injection supplies

BACKGROUND

In the United States, accessing sterile injection supplies remains challenging for many people who inject drugs (PWID). Although women are less likely to inject drugs than men, women who do inject are disproportionately affected by IDU-related complications. Needle Exchange Technology (NEXT), the first formal online accessed mail delivery syringe services program (SSP) in the US, may overcome access barriers. We evaluated whether NEXT was reaching women participants and people without access to other safe sources of sterile injection supplies.

METHODS

This cross-sectional study examined NEXT participants who enrolled in the mail-delivery SSP from February 2018 through March 2021. All NEXT participants completed an online questionnaire during enrollment, which included sociodemographic and clinical characteristics and injection-related risk factors (including prior sources of sterile injection supplies). Multivariable logistic regression (MVR) was used to examine associations between gender and prior use of safe sources of injection supplies (i.e., SSPs or pharmacies).

RESULTS

1,032 participants received injection supplies. Median age was 34 and participants were mostly cis-gendered women (55%) and white (93%). 34% reported infection with HCV; women were more likely to report HCV infection than men (38% vs 28%; p < 0.01). 68% of participants acquired injection supplies from less safe sources. Few participants exclusively used safe sources for injection supplies (26%). In adjusted MVR analysis, women participants had significantly lower odds than men of having exclusively used safe sources for injection supplies (adjusted OR 0.71, 95% CI 0.52, 0.98).

CONCLUSION

Our findings suggest that NEXT services are utilized by women and people without prior access to sterile injection supplies. Women participants were less likely than men to have exclusively used safe sources for sterile injection supplies. Future research should explore women's preference for mail-delivery over in-person SSPs and determine whether online accessed mail delivery services can reach other underserved populations of PWID.

Clinical impact, costs, and cost-effectiveness of hospital-based strategies for addressing the US opioid epidemic: a modelling study

Background

The syndemic of injection drug use and serious injection-related infections is leading to increasing mortality in the USA. Although outpatient treatment with medications for opioid use disorder reduces overdose risk and recurrent infections, hospitalisation remains common. We evaluated the clinical impact, costs, and cost-effectiveness of hospital-based strategies to address the US opioid epidemic.

Methods

We developed a microsimulation model to compare the cost-effectiveness of: standard hospital care—detoxification for opioids, no addiction consult service (status quo); expanded inpatient prescribing of medications for opioid use disorder, including bridge prescriptions (ie, medication until they can see an outpatient provider) when possible (medications for opioid use disorder with bridge); implementation of addiction consult services within the hospital (addiction consult services alone); and a combined medication for opioid use disorder with addiction consult services strategy (combined). We used clinical trials and observational cohorts to inform model inputs. Outcomes were life-years, discounted costs, incremental cost-effectiveness ratios, hospitalisations, and deaths. We did deterministic sensitivity analyses on key model inputs related to costs and sequelae of drug use and probabilistic sensitivity analysis to further address uncertainty.

Findings

Among people who inject opioids in the USA, we estimated that expanding medications for opioid use disorder with bridge prescriptions would reduce hospitalisations and overdose deaths by 3·2% and 3·6%, respectively, and the combination of expanded medications with opioid use disorder along with addiction consult sevices would reduce hospitalisations and overdoses by 5·2% and 6·6%, respectively, compared with the status quo. Mean lifetime costs ranged from US$731 400 (95% credible interval 447 911–859 189 for the medications for opioid use disorder strategy) to $741 200 (470 930–868 551 for the combined strategy) per person. Assuming a willingness-to-pay threshold of $100 000 per life-year gained, medications for opioid use disorder with bridge and combined strategies were cost-effective ($7600 and $14 300, respectively). A scenario that assumed ideal access to harm reduction services came to the same conclusions as the base case and our results were robust in deterministic and probabilistic sensitivity analyses.

Interpretation

The combined interventions of expanding hospital-based prescribing of medications for opioid use disorder and implementing addiction consult services could improve life expectancy, be cost-effective, and could be the basis for a comprehensive hospital-based strategy for addressing the opioid epidemic in the USA and countries with similar opioid epidemics.

Funding

National Institute on Drug Abuse and National Institute of Allergy and Infectious Diseases.

Is your syringe services program cost-saving to society? A methodological case study

BACKGROUND

While there is a general acceptance among public health officials and policy-makers that syringe services programs can be effective in reducing HIV transmission among persons who inject drugs, local syringe services programs are often asked to provide economic justifications for their activities. A cost-effectiveness study, estimating the cost of preventing one HIV infection, would be the preferred methods for addressing this economic question, but few local syringe services programs have the needed data, staff and epidemiologic modeling resources needed for a cost-effectiveness study. We present a method for estimating a threshold value for the number of HIV infections prevented above which the program will be cost-saving to society. An intervention is considered "cost-saving" when it leads to a desirable health outcome a lower cost than the alternative.

METHODS

The research literature on the effectiveness of syringe services programs in controlling HIV transmission among persons who inject drugs and guidelines for syringe services program that are "functioning very well" were used to estimate the cost-saving threshold at which a syringe services program becomes cost-saving through preventing HIV infections versus lifetime treatment of HIV. Three steps are involved: (1) determining if HIV transmission in the local persons who inject drugs (PWID) population is being controlled, (2) determining if the local syringe services program is functioning very well, and then (3) dividing the annual budget of the syringe services program by the lifetime cost of treating a single HIV infection.

RESULTS

A syringe services program in an area with controlled HIV transmission (with HIV incidence of 1/100 person-years or less), functioning very well (with high syringe coverage, linkages to other services, and monitoring the local drug use situation), and an annual budget of $500,000 would need to prevent only 3 new HIV infections per year to be cost-saving.

CONCLUSIONS

Given the high costs of treating HIV infections, syringe services programs that are operating according to very good practices ("functioning very well") and in communities in which HIV transmission is being controlled among persons who inject drugs, will almost certainly be cost-saving to society.

Assessing the relationship between syringe exchange, pharmacy, and street sources of accessing syringes and injection drug use behavior in a pooled nationally representative sample of people who inject drugs in the United States from 2002 to 2019

Provision of sterile syringes is an evidence-based strategy of reducing syringe sharing and reusing and yet, access to sterile syringes through pharmacies and syringe exchange programs (SEPs) in the United States remains inadequate. This nationally representative study examined associations between obtaining syringes from pharmacies, SEPs, and sterilizing syringes with bleach and risk of syringe borrowing, lending and reusing syringes in a pooled cross-sectional dataset of 1737 PWID from the 2002-2019 National Survey on Drug Use and Health. Logistic regression was used to produce odds ratios (OR) of the odds of injection drug behaviors after adjusting for obtaining syringes from SEPs, pharmacies, the street, and other sources and potential confounders of race, ethnicity, sex, education, and insurance coverage. Obtaining syringes through SEPs was associated with lower odds of borrowing (OR = .4, CI95% = .2, .9, p = .022) and reusing syringes (OR = .3, CI95% = .2, .6, < .001) compared to obtaining syringes on the street. Obtaining syringes from pharmacies was associated with lower odds of borrowing (OR = .5, CI95% = .3, .9, p = .037) and lending (OR = .5 CI95% = .3, .9, p = .020) syringes. Using bleach to clean syringes was associated with increased odds of borrowing (OR = 2.0, CI95% = 1.3, 3.0, p = .002), lending (OR = 2.0, CI95% = 1.3, 3.0, p = .002) and reusing syringes (OR = 2.4, CI95% = 1.6, 3.6, p < .001). Our findings support provision of syringes through pharmacies and SEPs as a gold-standard strategy of reducing sharing and reuse of syringes in the US.

Routes of Administration of Illicit Drugs among Young Swiss Men: Their Prevalence and Associated Socio-Demographic Characteristics and Adverse Outcomes

The prevalence of different routes of administration (ROAs) of illicit drugs other than cannabis was examined in young Swiss men, in addition to the association between socio-demographics and adverse outcomes and particular ROAs. Our sample consisted of 754 men (mean age = 25.4 ± 1.2 years) who participated in the Cohort Study on Substance Use Risk Factors and reported using any of 18 illicit drugs over the last 12 months. Prevalence estimates were calculated for oral use, nasal use, smoking, injecting, and other ROAs. Associations between ROAs and socio-demographics and adverse outcomes (i.e., alcohol use disorder (AUD), suicidal ideations, and health and social consequences) were calculated for using single versus multiple ROAs. The most prevalent ROA was oral use (71.8%), followed by nasal use (59.2%), smoking (22.1%), injecting (1.1%), and other ROAs (1.7%). Subjects’ education, financial autonomy, and civil status were associated with specific ROAs. Smoking was associated with suicidal ideations and adverse health consequences and multiple ROAs with AUD, suicidal ideations, and health and social consequences. The most problematic pattern of drug use among young adults appears to be using multiple ROAs, followed by smoking. Strategies to prevent and reduce the use of such practices are needed to avoid adverse outcomes at this young age.

Transition from injecting opioids to smoking fentanyl in San Francisco, California

BACKGROUND

The introduction of illicitly made fentanyl in the United States has slowly replaced heroin. New illicit drugs are often associated with changes in frequency and modes of administration. We assessed changes in injection frequency and smoking fentanyl in the new era of fentanyl availability in San Francisco.

METHODS

We used targeted sampling to recruit 395 people who inject drugs (PWID) into an observational cohort study in San Francisco 2018-2020. We assessed changes in injection frequency, opioid injection frequency and fentanyl smoking frequency in four six-month periods. We also conducted qualitative interviews with PWID asking about motivations for injecting and smoking opioids.

RESULTS

The median number of past-month injections steadily decreased by semi-annual calendar year from 92 injections in July to December 2018 to 17 injections in January to June 2020. The rate of opioid injections reduced by half (Adjusted Incidence Rate Ratio = 0.41; 95 % Confidence Interval = 0.25, 0.70; p < 0.01). The number of days smoking fentanyl was associated with fewer number of injections (X2(2) = 11.0; p < 0.01). Qualitative interviews revealed that PWID's motivation for switching from injecting tar heroin to smoking fentanyl was related to difficulties accessing veins. After switching to smoking fentanyl, they noticed many benefits including how the drug felt, improved health, fewer financial constraints, and reduced stigma.

CONCLUSION

Between 2018 and 2020, there was a shift from injecting tar heroin to smoking fentanyl in San Francisco. Reductions in injection of illicit drugs may offer public health benefit if it reduces risk of blood-borne viruses, abscesses and soft-tissue infections, and infective endocarditis.

Syringe Coverage Among People Who Inject Drugs in West Virginia, USA

Ensuring people who inject drugs (PWID) have ≥ 100% sterile syringe coverage (i.e., persons have access to a sterile syringe for all injections) is optimal for HIV prevention. Existing syringe coverage literature is informative, yet little work has examined syringe coverage among PWID in rural communities. Using data from a 2018 PWID population estimation study conducted in a rural county in West Virginia, we used logistic regression to identify correlates of adequate sterile syringe coverage (at least 100%). A minority (37%) of PWID reported having adequate syringe coverage. Factors inversely associated with adequate syringe coverage included having recently (past 6 months): engaged in transactional sex work, shared syringes, and injected fentanyl. Having exclusively acquired syringes from a syringe services program was associated with increased odds of adequate syringe coverage. Rural PWID may benefit from tailored interventions designed to increase sterile syringe access.

The Surgical Treatment of Deep Infection in the Native Shoulder Joint

Background

The overall clinical picture surrounding native shoulder infections, and, in particular, the associated long-term functional outcomes of treatment are presently underreported. The purpose of this study is to examine the demographics, diagnostic and treatment strategies, and functional outcomes of isolated shoulder joint sepsis treated with surgical irrigation and debridement (I&D).

Methods

All patients treated with I&D for native shoulder sepsis between 2007 - 2017 were identified. Those without a minimum of one-year follow-up were excluded. Functional outcomes scores, reoperations, and predictors of poor outcome were evaluated.

Results

Twenty-three patients were included in the final study population. Mean age-adjusted CCI score was 4.1 (SD = 3.4, Range = 0 - 10). Twelve patients (52.2%) were treated with open I&D, while 11 patients (47.8%) were treated arthroscopically. Nine patients (39.1%) required multiple I&Ds (mean total number of I&Ds = 1.7, SD = 1.0, Range: 1 - 4). Five patients (21.7%) had at least one documented reinfection after their initial hospitalization, with the initial recurrence of infection occurring 2 - 15 months after the index procedure. Mean ASES score at final follow-up was 55.3 (SD = 26.7, Range: 5.8 - 98.3) and mean SANE score was 53.3 (SD = 30.6, Range: 0 - 100). Stepwise multiple linear regression modeling identified intravenous drug abuse as the most significant predictor for final ASES score [F(1,18) = 6.12, p = .024, adjusted R² = .254].

Conclusion

Following isolated shoulder joint sepsis, infection clearance and acceptable functional outcomes can be achieved using surgical I&D followed by a course of antibiotics, but outcomes are variable.

Potential Contributions of Clinical and Community Testing in Identifying Persons with Undiagnosed HIV Infection in the United States

BACKGROUND

An estimated 166,155 individuals in the United States have undiagnosed HIV infection. We modeled the numbers of HIV-infected individuals who could be diagnosed in clinical and community settings by broadly implementing HIV screening guidelines.

SETTING

United States.

METHODS

We modeled testing for general population (once lifetime) and high-risk populations (annual): men who have sex with men, people who inject drugs, and high-risk heterosexuals. We used published data on HIV infections, HIV testing, engagement in clinical care, and risk status disclosure.

RESULTS

In clinical settings, about 76 million never-tested low-risk and 2.6 million high-risk individuals would be tested, yielding 36,000 and 55,000 HIV diagnoses, respectively. In community settings, 30 million low-risk and 4.4 million high-risk individuals would be tested, yielding 75,000 HIV diagnoses.

CONCLUSION

HIV testing in clinical and community settings diagnoses similar numbers of individuals. Lifetime and risk-based testing are both needed to substantially reduce undiagnosed HIV.

Disparities in risk perception and low harm reduction services awareness, access, and utilization among young people with newly reported hepatitis C infections in California, 2018

Background

Newly reported hepatitis C virus (HCV) infections in California increased 50% among people 15–29 years of age between 2014 and 2016. National estimates suggest this increase was due to the opioid epidemic and associated increases in injection drug use. However, most of California’s 61 local health jurisdictions (LHJs) do not routinely investigate newly reported HCV infections, so these individuals’ risk factors for infection are not well understood. We sought to describe the demographics, risk behaviors, and utilization of harm reduction services in California’s fastest-rising age group of people with newly reported hepatitis C infections to support targeted HCV prevention and treatment strategies.

Methods

California Department of Public Health invited LHJs to participate in enhanced surveillance if they met criteria indicating heightened population risk for HCV infection among people ages 15–29. From June–December 2018, eight LHJs contacted newly reported HCV cases by phone using a structured questionnaire.

Results

Among 472 total HCV cases who met the inclusion criteria, 114 (24%) completed an interview. Twenty-seven percent of respondents (n = 31) had ever been incarcerated, of whom 29% received a tattoo/piercing and 39% injected drugs while incarcerated. Among people who injected drugs (PWID)—36% (n = 41) of all respondents—68% shared injection equipment and many lacked access to harm reduction services: 37% knew of or ever used a needle exchange and 44% ever needed naloxone during an overdose but did not have it. Heroin was the most frequently reported injected drug (n = 30), followed by methamphetamine (n = 18). Pre-diagnosis HCV risk perception varied significantly by PWID status and race/ethnicity: 76% of PWID vs. 8% of non-PWID (p < 0.001), and 44% of non-Hispanic White respondents vs. 22% of people of color (POC) respondents (p = 0.011), reported thinking they were at risk for HCV before diagnosis. Eighty-nine percent of all respondents reported having health insurance, although only two had taken HCV antiviral medications.

Conclusions

Among young people with HCV, we found limited pre-diagnosis HCV risk perception and access to harm reduction services, with racial/ethnic disparities. Interventions to increase harm reduction services awareness, access, and utilization among young PWID, especially young PWID of color, may be warranted.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-11492-3.

Can hepatitis C elimination targets be sustained among people who inject drugs post-2030?

BACKGROUND

In high-income countries, people who inject drugs (PWID) are a priority population for eliminating hepatitis C virus (HCV) by 2030. Despite evidence informing micro-elimination strategies, little is known regarding efforts needed to maintain elimination targets in populations with ongoing acquisition risks. This model-based study investigates post-elimination transmission dynamics of HCV and HIV among PWID under different scenarios where harm reduction interventions and HCV testing and treatment are scaled-down.

METHODS

We calibrated a dynamic compartmental model of concurrent HCV and HIV transmission among PWID in Montréal (Canada) to epidemiological data (2003-2018). We then simulated achieving the World Health Organization elimination targets by 2030. Finally, we assessed the impact of four post-elimination scenarios (2030-2050): 1) scaling-down testing, treatment, opioid agonist therapy (OAT), and needle and syringe programs (NSP) to pre-2020 levels; 2) only scaling-down testing and treatment; 3) suspending testing and treatment, while scaling down OAT and NSP to pre-2020 levels; 4) suspending testing and treatment and maintaining OAT and NSP coverage required for elimination.

RESULTS

Scaling down interventions to pre-2020 levels (scenario 1) leads to a modest rebound in chronic HCV incidence from 2.4 to 3.6 per 100 person-years by 2050 (95% credible interval - CrI: 0.8-7.2). When only scaling down testing and treatment (scenario 2), chronic HCV incidence continues to decrease. In scenario 3 (suspending treatment and scaling down OAT and NSP), HCV incidence and mortality rapidly increase to 11.4 per 100 person-years (95%CrI: 7.4-15.5) and 3.2 per 1000 person-years (95%CrI: 2.4-4.0), respectively. HCV resurgence was mitigated in scenario 4 (maintaining OAT and NSP) as compared to scenario 3. All scenarios lead to decreases in the proportion of reinfections among incident cases and have little impact on HIV incidence and HIV-HCV coinfection prevalence.

CONCLUSION

Despite ongoing transmission risks, HCV incidence rebounds slowly after 2030 under pre-2020 testing and treatment levels. This is heightened by maintaining high-coverage harm reduction interventions. Overall, sustaining elimination would require considerably less effort than achieving it.

Impact of Chronic Hepatitis C virus co-infection on outcomes of infective endocarditis in people who inject drugs

Injection drug use (IDU) is a risk factor for infective endocarditis (IE) and hepatitis C virus (HCV) infection. This retrospective cohort study assessed HCV's impact on outcomes of adult people who inject drugs (PWID). Those admitted due to IE using modified Duke criteria from January 2012 through May 2018 were identified. The cohort was divided into HCV seropositive and seronegative groups. The seropositive group was further stratified according to HCV viremia. Complications and mortality during the IE hospitalization, at 10 weeks, and 1 year were compared across groups. Clinical factors were similar between the cohorts, except patients without viremia (29, 81%) required more ICU admissions than with viremia (30, 60%) (P < 0.05). There was no difference in mortality at all time periods between the groups. Although several factors affect mortality in PWID with IE, neither HCV antibody positivity nor viremia appear to increase the risk for complications or death.

Risk factors for loss to follow-up of persons who inject drugs enrolled at syringe services programs in Kentucky

BACKGROUND

Syringe services programs (SSP) are an effective strategy to reduce blood-borne infections of human immunodeficiency virus (HIV) and hepatitis C virus (HCV) in persons who inject drugs (PWID). The objectives of this study were to determine the frequency and risk factors for loss to follow-up (LTFU) in PWID enrolled at SSPs in Kentucky.

METHODS

A retrospective cohort study was conducted which included data of PWID enrolled at 32 SSP. Demographics, use of drugs, HIV testing, HCV testing, and medical services were analyzed. A generalized linear model (GLM), family binomial was used to determine risk factors for LTFU.

RESULTS

The analysis included 5742 PWID. LTFU by year of enrollment was 287/770 (37.3%) in 2017, 796/1874 (42.5%) in 2018, and 1479/3,098 (47.7%) in 2019. LTFU was significantly associated with distance to SSP from home of more than five miles (RR 1.25; 95%CI 1.09-1.43; p = 0.002) and SSPs housed in rural counties (RR 1.22; 95%CI 1.06-1.40; p = 0.004), adjusted by age, sex, and race. The use of buprenorphine was associated with less risk of LTFU (RR 0.79, p = 0.034).

CONCLUSION

The distance to an SSP from home and SSPs in rural counties were identified as risk factors for LTFU. Initiatives that bring health services closer to PWID homes and offer opioid use disorder treatment may improve repeated participation in SSPs.

Epidemiology of HIV in the USA: epidemic burden, inequities, contexts, and responses

The HIV epidemic in the USA began as a bicoastal epidemic focused in large cities but, over nearly four decades, the epidemiology of HIV has changed. Public health surveillance data can inform an understanding of the evolution of the HIV epidemic in terms of the populations and geographical areas most affected. We analysed publicly available HIV surveillance data and census data to describe: current HIV prevalence and new HIV diagnoses by region, race or ethnicity, and age; trends in HIV diagnoses over time by HIV acquisition risk and age; and the distribution of HIV prevalence by geographical area. We reviewed published literature to explore the reasons for the current distribution of HIV cases and important disparities in HIV prevalence. We identified opportunities to improve public health surveillance systems and uses of data for planning and monitoring public health responses. The current US HIV epidemic is marked by geographical concentration in the US South and profound disparities between regions and by race or ethnicity. Rural areas vary in HIV prevalence; rural areas in the South are more likely to have a high HIV prevalence than rural areas in other US Census regions. Ongoing disparities in HIV in the South are probably driven by the restricted expansion of Medicaid, health-care provider shortages, low health literacy, and HIV stigma. HIV diagnoses overall declined in 2009-18, but HIV diagnoses among individuals aged 25-34 years increased during the same period. HIV diagnoses decreased for all risk groups in 2009-18; among men who have sex with men (MSM), new diagnoses decreased overall and for White MSM, remained stable for Black MSM, and increased for Hispanic or Latino MSM. Surveillance data indicate profound and ongoing disparities in HIV cases, with disproportionate impact among people in the South, racial or ethnic minorities, and MSM.

National Public Health Burden Estimates of Endocarditis and Skin and Soft-Tissue Infections Related to Injection Drug Use: A Review

BACKGROUND

Despite concerns about the burden of the bacterial and fungal infection syndromes related to injection drug use (IDU), robust estimates of the public health burden of these conditions are lacking. The current article reviews and compares data sources and national burden estimates for infective endocarditis (IE) and skin and soft-tissue infections related to IDU in the United States.

METHODS

A literature review was conducted for estimates of skin and soft-tissue infection and endocarditis disease burden with related IDU or substance use disorder terms since 2011. A range of the burden is presented, based on different methods of obtaining national projections from available data sources or published data.

RESULTS

Estimates using available data suggest the number of hospital admissions for IE related to IDU ranged from 2900 admissions in 2013 to more than 20 000 in 2017. The only source of data available to estimate the annual number of hospitalizations and emergency department visits for skin and soft-tissue infections related to IDU yielded a crude estimate of 98 000 such visits. Including people who are not hospitalized, a crude calculation suggests that 155 000-540 000 skin infections related to IDU occur annually.

DISCUSSION

These estimates carry significant limitations. However, regardless of the source or method, the burden of disease appears substantial, with estimates of thousands of episodes of IE among persons with IDU and at least 100 000 persons who inject drugs (PWID) with skin and soft-tissue infections annually in the United States. Given the importance of these types of infections, more robust and reliable estimates are needed to better quantitate the occurrence and understand the impact of interventions.

Human Immunodeficiency Virus Testing, Diagnosis, Linkage to Care, and Prevention Services Among Persons Who Inject Drugs, United States, 2012-2017

BACKGROUND

Human immunodeficiency virus (HIV) testing and early diagnosis is associated with effective disease management and reduction in HIV transmission among persons who inject drugs (PWID). We examined trends in HIV testing outcomes among PWID during 2012-2017.

METHODS

Centers for Disease Control and Prevention (CDC)-funded HIV testing data submitted by 61 health departments and 150 directly-funded community-based organizations during 2012-2017 were analyzed. We calculated estimated annual percentage changes (EAPC) to assess trends for HIV testing and testing outcomes.

RESULTS

A total of 19 739 857 CDC-funded HIV tests were conducted during 2012-2017. Of these, 529 349 (2.7%) were among PWID. The percentage of newly diagnosed HIV increased from .7% in 2012 to .8% in 2017 (EAPC, 4.15%). The percentage interviewed for partner services increased from 46.7% in 2012 to 66.3% in 2017 (EAPC, 1.81%). No significant change was identified in trends for linkage to HIV medical care ≤90 days after diagnosis (EAPC, 0.52%) or referral to HIV prevention services (EAPC, 0.98%).

CONCLUSIONS

Human immunodeficiency virus testing data revealed an increasing trend in newly diagnosed HIV among PWID but not linkage to HIV medical care or referral to prevention services. Expanding efforts to increase HIV testing and enhance linkage to services can lead to reductions in HIV transmission and improved health outcomes.

Ending the HIV Epidemic Among Persons Who Inject Drugs: A Cost-Effectiveness Analysis in Six US Cities

BACKGROUND

Persons who inject drugs (PWID) are at a disproportionately high risk of HIV infection. We aimed to determine the highest-valued combination implementation strategies to reduce the burden of HIV among PWID in 6 US cities.

METHODS

Using a dynamic HIV transmission model calibrated for Atlanta, Baltimore, Los Angeles, Miami, New York City, and Seattle, we assessed the value of implementing combinations of evidence-based interventions at optimistic (drawn from best available evidence) or ideal (90% coverage) scale-up. We estimated reduction in HIV incidence among PWID, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs) for each city (10-year implementation; 20-year horizon; 2018 $ US).

RESULTS

Combinations that maximized health benefits contained between 6 (Atlanta and Seattle) and 12 (Miami) interventions with ICER values ranging from $94 069/QALY in Los Angeles to $146 256/QALY in Miami. These strategies reduced HIV incidence by 8.1% (credible interval [CI], 2.8%-13.2%) in Seattle and 54.4% (CI, 37.6%-73.9%) in Miami. Incidence reduction reached 16.1%-75.5% at ideal scale.

CONCLUSIONS

Evidence-based interventions targeted to PWID can deliver considerable value; however, ending the HIV epidemic among PWID will require innovative implementation strategies and supporting programs to reduce social and structural barriers to care.

Use of Population-Based Surveys for Estimating the Population Size of Persons Who Inject Drugs in the United States

BACKGROUND

In the United States, injection is an increasingly common route of administration for opioids and other substances. Estimates of the number of persons who inject drugs (PWID) are needed for monitoring risk-specific infectious disease rates and health services coverage.

METHODS

We reviewed design and instruments for 4 national household surveys, 2012-2016, for their ability to produce unbiased injection drug use (IDU) prevalence estimates. We explored potential analytic adjustments for reducing biases through use of external data on (1) arrest, (2) narcotic overdose mortality, and (3) biomarker-based sensitivity of self-reported illicit drug use.

RESULTS

Estimated national past 12 months IDU prevalence ranged from 0.24% to 0.59% across surveys. All surveys excluded unstably housed and incarcerated persons, and estimates were based on <60 respondents reporting IDU behavior in 3 surveys. No surveys asked participants about nonmedical injection of prescription drugs. Analytic adjustments did not appreciably change IDU prevalence estimates due to suboptimal specificity of data points.

CONCLUSIONS

PWID population size estimates in the United States are based on small numbers and are likely biased by undercoverage of key populations and self-report. Novel methods as discussed in this article may improve our understanding of PWID population size and their health needs.

High Inpatient Health Care Utilization and Charges Associated With Injection Drug Use-Related Infections: A Cohort Study, 2012-2015

Our study describes the characteristics of patients hospitalized with injection drug use–related infection over a multiyear period in a region highly impacted by the opioid epidemic. Intensive health care needs were common in this young cohort, including high rates of readmission, high hospitalization costs, and prolonged lengths of stay.

Progression and transmission of HIV (PATH 4.0)-A new agent-based evolving network simulation for modeling HIV transmission clusters

We present the Progression and Transmission of HIV (PATH 4.0), a simulation tool for analyses of cluster detection and intervention strategies. Molecular clusters are groups of HIV infections that are genetically similar, indicating rapid HIV transmission where HIV prevention resources are needed to improve health outcomes and prevent new infections. PATH 4.0 was constructed using a newly developed agent-based evolving network modeling (ABENM) technique and evolving contact network algorithm (ECNA) for generating scale-free networks. ABENM and ECNA were developed to facilitate simulation of transmission networks for low-prevalence diseases, such as HIV, which creates computational challenges for current network simulation techniques. Simulating transmission networks is essential for studying network dynamics, including clusters. We validated PATH 4.0 by comparing simulated projections of HIV diagnoses with estimates from the National HIV Surveillance System (NHSS) for 2010-2017. We also applied a cluster generation algorithm to PATH 4.0 to estimate cluster features, including the distribution of persons with diagnosed HIV infection by cluster status and size and the size distribution of clusters. Simulated features matched well with NHSS estimates, which used molecular methods to detect clusters among HIV nucleotide sequences of persons with HIV diagnosed during 2015-2017. Cluster detection and response is a component of the U.S. Ending the HIV Epidemic strategy. While surveillance is critical for detecting clusters, a model in conjunction with surveillance can allow us to refine cluster detection methods, understand factors associated with cluster growth, and assess interventions to inform effective response strategies. As surveillance data are only available for cases that are diagnosed and reported, a model is a critical tool to understand the true size of clusters and assess key questions, such as the relative contributions of clusters to onward transmissions. We believe PATH 4.0 is the first modeling tool available to assess cluster detection and response at the national-level and could help inform the national strategic plan.

An Evaluation of Opioid Use in Black Communities: A Rapid Review of the Literature

BACKGROUND

There are multiple aspects of the opioid crisis among Black people, who have been left out of the broader conversation. Despite evidence of increased opioid overdose deaths, less is known about opioid use among Black people. This review synthesizes research on Black people who use opioids; the goals are to advance knowledge, highlight research gaps, and inform clinical practice.

METHODS

This rapid review investigating opioid use among Black people utilized systematic review methods and was conducted according to a predefined protocol with clear inclusion criteria (PROSPERO ID: 177071). A comprehensive search strategy was used, including published and gray-literature sources (i.e., literature that has not been formally published). A narrative summary of the results is presented.

RESULTS

A total of 76 works were selected for inclusion and full text review. Sex, age, geographic location, and involvement in the carceral system were associated with the use of opioids among Black individuals. Non-epidemiologic factors included treatment-seeking patterns, disparate clinician prescribing, and social determinants.

CONCLUSIONS

Through this rapid review we suggest three main areas of focus: (1) including culturally informed collection methods in epidemiologic surveys to accurately reflect prevalences, (2) funding research that specifically addresses the importance of culture in accessing treatment, and (3) directly studying how social determinants can improve or exacerbate health outcomes. Focusing on the unique needs of Black people who use opioids is warranted to increase treatment initiation and adherence among a population less likely to engage with the traditional health care system.

Research Synthesis, HIV Prevention Response, and Public Health: CDC's HIV/AIDS Prevention Research Synthesis Project

OBJECTIVE

Research synthesis, through qualitative or quantitative systematic reviews, allows for integrating results of primary research to improve public health. We examined more than 2 decades of work in HIV prevention by the Centers for Disease Control and Prevention's (CDC's) HIV/AIDS Prevention Research Synthesis (PRS) Project. We describe the context and contributions of research synthesis, including systematic reviews and meta-analyses, through the experience of the PRS Project.

METHODS

We reviewed PRS Project publications and products and summarized PRS contributions from 1996 to July 2020 in 4 areas: synthesis of interventions and epidemiologic studies, synthesis methods, prevention programs, and prevention policy.

RESULTS

PRS Project publications summarized risk behaviors and effects of prevention interventions (eg, changing one's perception of risk, teaching condom negotiation skills) across populations at risk for HIV infection and intervention approaches (eg, one-on-one or group meetings) as the HIV/AIDS epidemic and science evolved. We used the PRS Project cumulative database and intervention efficacy reviews to contribute to prevention programs and policies through identification of evidence-based interventions and development of program guidance. Subject matter experts and scientific evidence informed PRS Project products and contributions, which were implemented through strategic programmatic partnerships.

CONCLUSIONS

The contributions of the PRS Project to HIV prevention and public health efforts in the United States can be credited to CDC's long-standing support of the project and its context within a federal prevention agency, where HIV programs and policies were developed and implemented. The effect of the PRS Project was likely facilitated by opportunities to directly influence program and policy because of connections with other research translation activities and program and policy decision making within CDC.

"I probably got a minute": Perceptions of fentanyl test strip use among people who use stimulants

BACKGROUND

Fentanyl dominates the heroin supply in many regions of the United States. One harm reduction response has been the distribution of fentanyl test strips to people who use heroin to test for the presence of fentanyl. Reports increasingly indicate that fentanyl contamination is occurring in the illicit stimulant market, but whether people who use stimulants would use fentanyl test strips is unknown.

METHODS

Between January 2019 and January 2020, fifteen people in Philadelphia, PA who reported stimulant use completed a semi-structured interview with questions about their perceptions of fentanyl and willingness to use fentanyl test strips. Data were coded and analyzed for thematic content using constructs from the Health Belief Model and risk environment theory.

RESULTS

Participants primarily reported using crack cocaine or crack cocaine/heroin, while some used methamphetamine, powder cocaine, or prescription opioids. All were aware of fentanyl and believed they were susceptible to a fentanyl overdose as stimulant users. Participants perceived benefits of using test strips but reported barriers, such as the unpredictable nature of buying or using drugs and not wanting to delay drug use to test. Structural conditions impeded participant actions to reduce overdose risk if their drugs tested positive for fentanyl.

CONCLUSION

Fentanyl test strips were a desired harm reduction tool by many participants who used stimulants. In addition to providing access to the strips, programs should tailor overdose prevention education to these clients by acknowledging susceptibility, amplifying benefits, and addressing drug-specific barriers to use of fentanyl test strips.

Between Emergency Department Visits: The Role of Harm Reduction Programs in Mitigating the Harms Associated With Injection Drug Use

Injection drug use is a major public health problem in the United States. Cocaine, heroin, and methamphetamine are the most commonly injected illicit drugs, whereas opioids are responsible for the majority of overdose fatalities. Although recent emergency department (ED) efforts have focused on expanding capacity for buprenorphine induction for opioid use disorder treatment, the injection of illicit drugs carries specific health risks that require acknowledgment and management, particularly for patients who decline substance use treatment. Harm reduction is a public health approach that aims to reduce the harms associated with a health risk behavior, short of eliminating the behavior itself. Harm-reduction strategies fundamental to emergency medicine include naloxone distribution for opioid overdose. This clinical Review Article examines the specific health complications of injection drug use and reviews the evidence base for 2 interventions effective in reducing morbidity and mortality related to drug injection, irrespective of the specific drug used, that are less well known and infrequently leveraged by emergency medicine clinicians: syringe service programs and supervised injection facilities. In accordance with the recommendations of health authorities such as the Centers for Disease Control and Prevention, emergency clinicians can promote the use of harm-reduction programs in the community to reduce viral transmission and other risks of injection drug use by providing patients with information about and referrals to these programs after injection drug use-related ED visits.

Prevalence and correlates of receptive syringe-sharing among people who inject drugs in rural Appalachia

BACKGROUND AND AIMS

Syringe-sharing significantly increases the risk of HIV and viral hepatitis acquisition among people who inject drugs (PWID). Clearer understanding of the correlates of receptive syringe-sharing (RSS) is a critical step in preventing bloodborne infectious disease transmission among PWID in rural communities throughout the United States. This study aimed to measure the prevalence and correlates of RSS among PWID in a rural county in Appalachia.

DESIGN

Observational, cross-sectional sample from a capture-recapture parent study.

SETTING

Cabell County, West Virginia (WV), USA, June-July 2018.

PARTICIPANTS

The sample was restricted to people who reported injecting drugs in the past 6 months (n = 420). A total of 180 participants (43%) reported recent (past 6 months) RSS. Participants reported high levels of homelessness (56.0%), food insecurity (64.8%) and unemployment (66.0%).

MEASUREMENTS

The main outcome was recent re-use of syringes that participants knew someone else had used before them. Key explanatory variables of interest, selected from the risk environment framework, included: unemployment, arrest and receipt of sterile syringes from a syringe services program (SSP). Logistic regression was used to determine correlates of recent RSS.

FINDINGS

PWID reporting recent RSS also reported higher prevalence of homelessness, food insecurity and unemployment than their non-RSS-engaging counterparts. In adjusted analyses, correlates of RSS included: engagement in transactional sex work [adjusted odds ratio (aOR) = 2.27, 95% confidence interval (CI) = 1.26-4.09], unemployment (aOR = 1.67, 95% CI = 1.03-1.72), number of drug types injected (aOR = 1.33, 95% CI = 1.15-1.53) and injection in a public location (aOR = 2.59, 95% CI = 1.64-4.08). Having accessed sterile syringes at an SSP was protective against RSS (aOR = 0.57, 95% CI = 0.35-0.92).

CONCLUSION

The prevalence of receptive syringe-sharing among people who inject drugs in a rural US county appears to be high and comparable to urban-based populations. Receptive syringe-sharing among people who inject drugs in a rural setting appears to be associated with several structural and substance use factors, including unemployment and engaging in public injection drug use. Having recently acquired sterile syringes at a syringe services program appears to be protective against receptive syringe sharing.